The present invention relates generally to chucks for use with drills or with electric or pneumatic power drivers. More particularly, the present invention relates to a chuck of the keyless type that may be tightened or loosened by hand or by actuation of the driver motor.
Both hand and electric or pneumatic tool drivers are well known. Although twist drills are the most common tools on such drivers, the tools may also comprise screw drivers, nut drivers, burrs, mounted grinding stones, and other cutting or abrading tools. Since the tool shanks may be of varying diameter or of polygonal cross section, the device is usually provided with a chuck adjustable over a relatively wide range. The chuck may be attached to the driver by a threaded or tapered bore.
A variety of chucks have been developed in the art. In an oblique jawed chuck, a body member includes three passageways disposed approximately 120 apart from each other. The passageways are configured so that their centerlines meet at a point along the chuck axis forward of the chuck. The passageways constrain three jaws that are movable in the passageways to grip a cylindrical tool shank displaced approximately along the chuck center axis. The chuck includes a nut which rotates about the chuck center and which engages threads on the jaws so that rotation of the nut moves the jaws in either direction within the passageways. The body is attached onto the drive shaft of a driver and is configured so that rotation of the body in one direction with respect to the nut forces the jaws into gripping relationship with the tool shank, while rotation in the opposite direction releases the gripping relationship. Such a chuck may be keyless if it is rotated by hand. One example of such a chuck is disclosed in U.S. Pat. No. 5,125,673 entitled xe2x80x9cNon-impact Keyless Chuck,xe2x80x9d commonly assigned to the present assignee and the entire disclosure of which is incorporated by reference herein. Various configurations of keyless chucks are known in the art and are desirable for a variety of applications.
The present invention recognizes and addresses the foregoing considerations, and others, of prior art constructions and methods.
Accordingly, it is an object of the present invention to provide an improved chuck.
It is another object of the present invention to provide an improved mechanism for attaching the sleeve to the chuck.
These and other objects are achieved by providing a chuck for use with a manual or powered driver having a rotatable drive shaft. The chuck has a generally cylindrical body member with a forward section and a rearward section. The rearward section is configured to mate with the driver. The forward section has an axial bore formed therein and a plurality of angularly disposed passageways formed therethrough and intersecting the axial bore. The forward section also defines a ledge portion about its outer circumference and a front face transverse to the longitudinal axis of the body. A plurality of jaws are slidably positioned in each of the angularly disposed passageways. Each jaw has a jaw face formed on one side and threads formed on the other. A nut is rotatably mounted to the body rearward of the ledge so as to engage the jaw threads. A generally cylindrical sleeve has an annular open forward end and is received over the forward section of the body. The sleeve engages the nut so that when the sleeve is rotated, the nut will be rotated therewith to operate the jaws. The sleeve""s forward end includes an annular lip portion extending radially inward therefrom and at least partially covering the body""s front transverse face. The sleeve includes a flexible protrusion extending axially rearward from the inner circumference of the sleeve proximate the sleeve forward end. The protrusion includes a tab portion disposed rearward of the ledge portion and projecting radially inward of the outer circumference of the ledge portion to prevent forward axial movement of the sleeve with respect to the chuck body.
In one preferred embodiment, the forward end of the body is tapered so that the body""s outer diameter gradually increases rearwardly from the front face. When the sleeve is mounted onto the body, the tab bears against the tapered surface so that the protrusion deflects radially outward. The tab eventually snaps into the groove.
The sleeve may further include drive ribs that engage drive rib receiving slots on the nut. When the sleeve is rotated with respect to the body, the nut is rotated therewith. Therefore, rotation of the sleeve member actuates movement of the chuck jaws in either the forward or rearward direction depending on the direction of sleeve rotation.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one embodiment of the invention and, together with the description, serve to explain the principles of the invention.